This invention is directed toward a method and apparatus for beverage lines. More specifically, this invention is directed toward cleaning and sterilizing of beverage lines.
Cleaning retail beer, soda, wine, liquor, juice and condiment lines has been a necessary requirement for many years in order to maintain the taste and appearance of the beverages supplied through condiment lines. Specifically, as applied to beer and other associated beverage, line cleaning is required in order to ensure that the taste and appearance is of the same quality as brewery fresh beer. Numerous considerations are necessary to maintain draft beer quality standards, including but not limited to cooler management (such as proper temperature control, product rotation and the like) in addition to the quality and type of gas used to pressurize kegs and even the cleaning and proper serving techniques relating to the beer glass itself. However, even when all such conditions are perfect, proper maintenance and cleaning of the lines that deliver the beverage remains crucial, because improperly maintained beverage lines can single-handedly compromise the taste, appearance, and quality of the beverage, particularly due to the prevalence of “long line” technology over the past several years. As opposed to “under the bar” systems used in the past, the remote location of beer kegs has been increasing, as “long line” installations often utilize beverage lines which can be over 300 to 400 feet in length. Such installations have posed particular problems in terms of maintenance, sterilization, and cleaning, adversely impacting sales as draft beer for a retailer is a major profit center and sampling point for retailers, in addition condiments or food can pose health risks to consumers.
As compared to the surface to product ratio of a keg, the surface to product contact ratio in such long beverage lines is magnified thousands of times when a beverage such as beer is actively drawn to flow through the potentially hundreds of feet of beverage line from a remote keg to the point of dispensing, and the contact ratio is magnified even further when the beer is maintained stagnant in the line in between servings. Thus, the physical and biological cleanliness of these lines is critical to taste, physical appearance and foam quality of the product being served, as the accumulation of various substances which soil the lines alone can serve to destroy the quality of the product in an otherwise perfect beverage installation and dispensing system. Unfortunately, the substances present in such beverage lines have posed a particular problem in terms of sanitization, maintenance, sterilization and cleanliness due to the unique characteristics of the soiling substances produced by the beer and beverages flowing through such lines.
Biofilms, layers of microorganisms and other materials adhering to the surfaces of beverage lines constitute a serious problem in food and beverage lines. Microorganisms such as lactobacillus brevis, endobacter agglomerans, various species of the genus acetobacter, along with yeasts, molds, and other bacteria, hop resins, mineral crystals, protein, carbohydrates, silica gel, fibers, diatomaceous earth, sodium carbonate and other materials form biofilms and soils on the inner surfaces of lines which are deposited and accumulate over time as beer and other beverages flow through beverage lines, serving not only to adversely impact the quality, appearance and taste of the beverage, but also present health concerns for food products, leading to spoilage. Such substances formed on the line walls not only present beverage quality and health concerns, but also are particularly problematic with respect to accumulation and removal, making the cleaning and removal process virtually impossible in a reasonable fashion.
The foregoing substances in addition to biofilms formed by microbial cells, extra cellular polymers, and abiotic particles, once formed, can retard diffusion inside the biofilm, forming a barrier preventing penetration due to the use of cleaning solutions. The biomass and soils adhere to the walls of the line by mechanical and biological means; formation begins with the attachment of free-floating organisms to a surface of the beverage line. Unless the colonists are immediately separated from the surface, the arrival of other cells is facilitated by the provision of more diverse adhesion sites building a resistant matrix holding the biofilms together. The colonist also protects the cells contained therein and facilitates communication, additional breeding and growth. This forms a dense inter and extra cellular matrix with a boundary layer which is not only resistant to detergents, antibiotics and disinfectants but also can potentially become fossilized. Consequently, such conditions facilitate exponential growth, as the formed biofilms provide a breeding ground for explosive growth of the above organisms that cause undesired flavors, particulate matter, and poor foam quality in the beer.
Many methods and systems have been developed to clean and sterilize beverage lines, attempting to improve upon existing long line cleaning systems. Great effort has been made to develop an effective composition of a cleaning solution in order to remove soils more effectively. In addition, other cleaning and sterilization techniques have been developed such as mechanical methods and physical methods (such as sponges). These methods have been met with only moderate success due to in-line restrictions due to the dimensional characteristics of the long line beverage lines.
Other cleaning and sterilization systems have been developed which have utilized pumps to utilize turbulent flow as defined by Reynolds number. Turbulent flow usually occurs at high flow rates and/or in larger diameter pipes and is characterized by chaotic, irregularly mixing fluid with constant changes in the flow's behavior, including wakes, vortexes, and eddies, making flow rates impossible to accurately measure. Turbulent flow is usually desirable when solids must remain suspended in the fluid to prevent settling or blockages; however, Reynolds numbers and systems utilizing turbulent flow lose significance and are ineffective when dealing with smaller diameter beverage and beer lines. Such systems do not have the capacity to lift out solid soils nor remove soils adhering to the line walls.
Many recognized methods employ one or more of the aforementioned techniques with varying degrees of success, such as “pot cleaning,” utilizing a static liquid cleaning compound which is then pushed, which is usually done with carbon dioxide, air or gas. However, pot cleaning produces an undesired effect; because carbon dioxide is an acid in water the carbon dioxide reacts with the basic cleaner to form sodium carbonate which joins the biomass as a mineral salt.
Sponge cleaning involves inserting a sponge in the beverage line which is subsequently pushed through the line with liquid. In addition to the aforementioned limitations, sponge cleaning is characterized by additional deficiencies as sponges often become stuck due to line restrictions and are unsanitary.
Additional methods and systems include “circulation cleaning” wherein cleaning liquid is circulated through the lines, and “ultrasonic cleaning” involving an ultrasonic device placed on the line to discourage biofilm adhesion. Still, no current system or method is available which effectively penetrates the critical boundary layer of the liquid flow in the line, to engage the interior boundary at which the majority of the soil adheres to the walls of the beverage lines by mechanical and biological means, particularly in beverage lines with smaller diameters. As a result, a need has arisen for a sterilizing and cleaning system for beer and beverage lines which improves upon and overcomes the problems associated with existing systems which is fast, versatile and effective on all beverage lines.
Therefore a primary object of this invention is to provide a method and apparatus for cleaning and sterilizing beverage lines that improves cleaning performance.
It is yet another object of this invention to provide a method and apparatus for cleaning and sterilizing beverage lines that requires less cleaning solution, less chemical volume, and less chemical strength.
A further object of this invention is to provide a method and apparatus for cleaning and sterilizing beverage lines that provides a greater degree of mechanical cleaning action.
These and other objects, features or advantages of the present invention will become apparent from the specification and claims.